In the campaign, this weapon can only be used in the level "The Sins of the Father" as a starting weapon, although it comes with little ammo. It is possible to replenish the ammo for it, as it shares ammo with G3. In "Heat", Mac is heard providing sniper support with what sounds to be an R700, however, the player cannot obtain it in this level. The R700 is the only bolt-action rifle to be obtainable in the campaign, as the M40A3 is exclusive to multiplayer.

In Call of Duty 4: Modern Warfare's multiplayer, the R700 is the fourth sniper rifle to be unlocked. It is much like the M40A3, except it only holds four rounds, has more reliable damage multipliers, and has greater recoil and sway. However, with Stopping Power they both deal equal damage in most situations, making the M40A3 far superior if planning to use Stopping Power as a perk. When not using Stopping Power, it will kill in one shot to the head, chest or shoulders, doing the same damage as the Barrett .50cal and Dragunov. Being a low capacity bolt action rifle, the R700's greatest asset is its sheer stopping power. It can take out players using Juggernaut with a shot to the chest, neck, or head while used with Stopping Power.

The R700's sway is set to six degrees whereas all other sniper rifles are set to four degrees; meaning that the R700 will move more if breath is not held, and it takes longer to steady while a player is holding their breath.